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Item type:Publication, Gamma-ray irradiation effect on planar defect evolution of lattice-matched InGaAsN/GaAs/Ge grown by MOVPE(2024-09-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Comparison of thermoelectric properties of flexible bismuth telluride thin films deposited via DC and RF magnetron sputtering(2019-11-18); Bi<inf>2</inf>Te<inf>3</inf> thin films were deposited onto polyamide sheets with direct current (DC) or radio frequency (RF) magnetron sputtering techniques. The films were prepared using a Bi<inf>2</inf>Te<inf>3</inf> target at a varying pre-heating temperature from 150 to 350 °C. It was observed that the type of plasma excitation and pre-heating temperature can significantly change the composition, preferred orientation, crystallinity, and thermoelectric properties of the films. The pre-heat treatment significantly affected the non-stoichiometric composition. In addition, it was shown that crystallinity and (0 0 l) planes were enhanced in the DC sputtered coatings at a high pre-heating temperature. The maximum power factor of 3.5 × 10<sup>−3</sup> W/m K<sup>2</sup> at 285 °C was obtained for the films deposited using DC magnetron sputtering and a pre-heating temperature of 350 °C. The carrier concentration and mobility of the film were 5.40 × 10<sup>20</sup> cm<sup>−3</sup> and 13.04 cm<sup>2</sup>/V s, respectively. Compared with an ordinary Bi<inf>2</inf>Te<inf>3</inf> film, the power factor of such film has been greatly increased. The results indicated that DC magnetron sputtering can enhance the (0 0l) plane orientation in the Bi<inf>2</inf>Te<inf>3</inf> film. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Experimental Study on Flexible Bismuth Telluride Thin Films Deposited by DC Sputtering at Different Powers(2019-06-15); 1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of Grain Size and Film Thickness on the Thermoelectric Properties of Flexible Sb2Te3 Thin Films(2019-01-01); ; In this work, stoichiometric Sb<inf>2</inf>Te<inf>3</inf> thin films with various thicknesses were deposited on a flexible substrate using RF magnetron sputtering. The grain size and thickness effects on the thermoelectric properties, such as the Seebeck coefficient (S), electrical conductivity (σ), power factor (PF), and thermal conductivity (k), were investigated. The results show that the grain size was directly related to film thickness. As the film thickness increased, the grain size also increased. The Seebeck coefficient and electrical conductivity corresponded to the grain size of the films. The mean free path of carriers increases as the grain size increases, resulting in a decrease in the Seebeck coefficient and increase in electrical conductivity. Electrical conductivity strongly affects the temperature dependence of PF which results in the highest value of 7.5 × 10<sup>-4</sup> W/m·K<sup>2</sup> at 250°C for film thickness thicker than 1 μm. In the thermal conductivity mechanism, film thickness affects the dominance of phonons or carriers. For film thicknesses less than 1 μm, the behaviour of the phonons is dominant, while both are dominant for film thicknesses greater than 1 μm. Control of the grain size and film thickness is thus critical for controlling the performance of Sb<inf>2</inf>Te<inf>3</inf> thin films.